AVIAN INFLUENZA
Overview
Avian influenza (or bird flu) is a poultry disease caused by viruses that normally infect birds. This disease is caused by a number of type A influenza viruses.
Domestic poultry may be infected with one of two types of avian influenza viruses:
- The highly pathogenic viruses spread quickly and may kill nearly an entire poultry flock within 48 hours.
- The low pathogenic viruses cause only mild symptoms in chickens (such as ruffled feathers or a drop in egg production).
These avian influenza viruses usually do not infect humans. However, cases have occurred in humans outside the United States. The disease can be transmitted to poultry workers or others who contact infected poultry or contaminated surfaces. Examples of workers at risk include the following:
- Poultry growers and their workers
- Service technicians of poultry processing companies
- Caretakers, layer barn workers, and chick workers at egg production facilities
- Workers involved in disease control and eradication (including Federal, contract, and company workers)

Photos courtesy of U. S. Department of Agriculture
The first cases of human infection with the highly pathogenic avian influenza virus H5N1 occurred in 1997 in Hong Kong. This virus probably originated from domestic poultry in that region. The current outbreaks of the H5N1 virus began in Asia in 2003. The H5N1 virus was recently reported in birds in Europe and Africa. This highly pathogenic virus has not been reported in birds or humans in the United States.
Scientists are concerned about the highly pathogenic H5N1 virus for three reasons:
- It threatens domestic poultry, especially chickens, throughout the world.
- It has passed from poultry to humans and caused serious illness and death.
- It may change into a form that is highly infectious in humans and spreads easily from person to person.
The H5N1 virus is excreted in the droppings, saliva, and nasal secretions of infected birds. The virus is believed to enter humans through the mouth, nose, eyes, and lungs. Scientists believe that the virus has been transmitted to humans from contact with one of the following:
- Infected poultry that was sick or dead
- Droppings of infected poultry
- Contaminated litter
- Contaminated surfaces such as egg collection containers
Although the human health risk of exposure to low pathogenic avian influenza viruses is not known, protective measures should be taken for anyone likely to have prolonged exposure to any avian influenza virus in an enclosed setting.
CDC Avian Influenza Resources
NIOSH Alert: Protecting Poultry Workers from Avian Influenza (Bird Flu)
DHHS (NIOSH) Publication No. 2008-128 (2008)
Provides guidance to employers and workers about protecting poultry workers from exposure to avian influenza viruses (May 2008).
En Español
CDC Avian Influenza Home Page
Provides comprehensive information about avian influenza, including recent outbreaks, the viruses, and the risk to human health. Provides links to guidance for specific industries and workers.
En Español
CDC/Council of State and Territorial Epidemiologists (CSTE) Rapid Response Training: The Role of Public Health in a Multi-Agency Response to Avian Influenza in the United States
Provides course materials to guide state and local health departments in identifying and controlling human infections and illness associated with high pathogenicity avian influenza. Includes personal protective equipment information and a poultry farm investigation exercise (2007).
CDC Interim Guidance for States Conducting Avian Mortality Surveillance for West Nile Virus and/or Highly Pathogenic H5N1 Avian Influenza Virus [PDF - 48 KB]
Provides guidance directed to state health departments to support avian
mortality surveillance. Provides general precautions for collecting single
dead birds, additional precautions for higher-risk settings, and recommendations for personal protective equipment disinfection and laboratory biosafety (August 2006).
CDC Interim Recommendations for Persons with Possible Exposure to Avian Influenza During Outbreaks Among Poultry in the United States
Describes the 2004 avian influenza outbreak in Texas and provides interim guidance for persons who might be exposed to avian influenza; health-care professionals; and consumers of poultry (February 2004).
En
Español
CDC Interim Guidance for Protection of Persons Involved in U.S. Avian Influenza Outbreak Disease Control and Eradication Activities
Provides interim guidance for protection of persons involved in activities to control and eradicate outbreaks of avian influenza among poultry in the United States (January 2006).
En
Español
CDC Webcast Symposium on Avian Influenza for State Health Departments and Poultry
Industry; Includes Worker Health and Safety Presentation
Provides transcripts and presentations on worker health and
safety, the public health impact of avian influenza, food safety issues,
and biosecurity on the farm by experts in public health and animal health
(November 2004).
CDC Interim Guidance for Airline Flight Crews and Persons Meeting Passengers Arriving from Areas with Avian Influenza (Updated)
Informs airline flight crews and personnel meeting arriving passengers
about appropriate precautions in the event they must interact with a person suspected of having avian influenza. Recommendations are based on standard infection control practices used in healthcare settings and on available information about the virus that causes avian influenza (March 2006).
En
Español
CDC Interim Guidance for Airline Cleaning Crew, Maintenance Crew, and Baggage/Package and Cargo Handlers for Airlines Returning from Areas Affected by Avian Influenza A (H5N1)
Informs personnel who clean, maintain, or remove baggage or packages from commercial and cargo airlines about appropriate precautions related to avian influenza A (H5N1) (March 2006).
En
Español
CDC Interim Guidance for Cleaning Aircraft Exteriors after Collisions with Birds in Avian Influenza A (H5N1)-Affected Areas
Provides workers with cleaning recommendations if a bird strike has occurred to an airplane taking off from, flying over, or landing in one of the
H5N1-affected countries (July 2006).
Other U.S. Avian Influenza Resources
OSHA Safety and Health Information Bulletin:
Avian
Influenza: Protecting Poultry Workers at Risk
A product of the OSHA-NIOSH Issues Exchange Group that presents basic
information about avian influenza viruses and describes measures for protecting and minimizing exposure of poultry workers to the virus (highlighted above).
OSHA Guidance
for Protecting Workers Against Avian Flu
Provides updated guidance, quick cards, and a fact sheet about avian
influenza. Information is provided for poultry, laboratory, and health
care workers, animal handlers, food handlers, airport personnel, employees
working abroad, and other worker groups at risk.
Department of Health and Human Services: Avian and Pandemic Health and Safety Page
Provides access to comprehensive U.S. government health and safety information about avian and pandemic influenza including worker resources.
En Español
U.S. Department of Agriculture (USDA) Avian Influenza SiteProvides news releases, fact sheets, and resources on avian influenza and highly pathogenic avian influenza.
National Institute of Environmental Health Sciences (NIEHS) Worker Education Training Program (WETP) Avian Influenza Site
Provides resources for avian influenza outbreak responders and other workplace resources.
NIEHS WETP Avian Responder Conference Site
Provides presentations and information about protecting avian influenza outbreak responders from the September 2007 NIEHS WETP conference.
U.S. Geological Survey (USGS) National Wildlife Health Center (NWHC), Avian Influenza Site
Provides information about avian influenza in wild birds in the
United States and around the world.
USGS NWHC Wildlife Health Bulletin 05-03: Safety Guidelines for Handling Wild Birds
Provides guidance for field biologists and others working with or handling wild
birds with specific reference to highly pathogenic avian influenza (August 2005).
U.S. Environmental Protection Agency (EPA) Document: Disposal of Domestic Birds Infected by Avian Influenza: An Overview of Considerations and Options
Provides information about domestic bird carcass management options, equipment
cleaning and disinfection, transportation, and personal protective equipment.
Provides contact information for appropriate response organizations (August
2006).
U.S. EPA Fact Sheet: Antimicrobial Products to Disinfect Poultry and Other
Facilities Against Avian Flu
Provides information about disinfectant products registered for use against
avian influenza A viruses.
En
Español
Delmarva Avian Influenza Joint Task Force, Interim Guidance for Implementation of CDC and OSHA Avian Influenza Recommendations
Provides interim guidance on worker training, infection control, use of personal
protective equipment, decontamination, vaccine and antiviral use, surveillance
for illness, and evaluation of persons who become ill.
National Chicken Council (NCC) Questions and Answers on Avian Influenza
Provides questions and answers on avian influenza from the NCC, the national, non-profit trade association representing the U.S. chicken industry.
Alaska Department of Fish and Game: What Hunters Should Know about Avian Influenza
Provides preventive recommendations for hunters working with wild birds.
U.S. Resources for Poultry Workers
OSHA Quick Card for Poultry Employees: Protecting Yourself from Avian Flu
NIEHS WETP Booklet: Protecting Yourself from Avian Influenza
An awareness level health and safety resource for workers who might contact avian influenza-infected animals or contaminated materials.
USDA APHIS Biosecurity Site
Provides information about biosecurity practices for poultry, pet birds, and wild birds with tools such as fact sheets, booklets, brochures, and posters.
Delmarva Avian Influenza Joint Task Force: Answers to Common Questions about
Avian Influenza for Poultry Growers
Provides information about biosecurity, infection control, and prevention recommendations.
University of Maryland: Understanding Avian Influenza Provides farm and business resources including biosecurity recommendations for specific groups of poultry workers such as vaccination crews, live-haul crews, and technical service workers.
International Avian Influenza Resources
Disclaimer:These resources are developed by government agencies whose safety and health practices and recommendations may differ from those of the United States
World Health Organization (WHO) Avian Influenza Site
Provides international guidelines, recommendations, reports,
and updated information on the status and impact of avian influenza
activities and outbreaks around the world.
En
Español
WHO Avian Influenza Interim Infection Control Guidelines for Health Care Facilities
Provides comprehensive guidelines for health care facility exposures,
including personal protective equipment recommendations.
PDF [PDF - 211 KB]
Provides concise recommendations about infection control for avian influenza. [PDF - 1.17 MB]
WHO Interim Guidelines for the Protection of Persons Involved in the Mass Slaughter of Animals Potentially Infected with Highly Pathogenic Avian Influenza Viruses [PDF - 765 KB]
Provides guidelines for worker protection including appropriate personal protective equipment.
WHO Guide for Field Operations: Collecting, Preserving and Shipping Specimens for the Diagnosis of Avian Influenza A(H5N1) Virus Infection
Provides worker safety information including recommendations for hand hygiene technique, respiratory protection, and disinfection (October 2006).
World Organization
for Animal Health (OIE) Avian Influenza Site
Provides information about the global distribution of avian influenza
and methods of controlling the disease in animals. En
Español
Food
and Agriculture Organization of the United Nations (FAO) Avian Influenza
Site
Provides information about avian influenza related to improved food security,
food safety, and safe trade in poultry and poultry products. Provides information
in support of the efforts to control highly pathogenic avian influenza in Asian
countries.
En
Español
European Centre for Disease Control and Prevention (ECDC) Avian Influenza Page
ECDC Guidelines to Minimise the Risk of Humans Acquiring Highly Pathogenic Avian Influenza From Exposure to Infected Birds or Animals [PDF - 715 KB]
Provides guidance for protecting workers from avian influenza exposure (December
2005).
Health and Safety Executive (HSE): Working with Highly Pathogenic Avian Influenza Virus
Provides guidance for workers and answers questions related to occupational exposure.
Provides guidance for avoiding infection when working with infected poultry. [PDF - 92 KB]
International Resources for Poultry Workers
Disclaimer:These resources are developed by government agencies whose safety and health practices and recommendations may differ from those of the United States
WHO Preventing Bird Flu: Precautions Poultry Farm Workers Should Take
FAO Avian Influenza Farming Systems Documents
Provides guidance for the prevention and control of avian influenza in small scale poultry. Documents are available in many languages and written for different countries including Cambodia and Vietnam.
En
Español
FAO: Protect Poultry, Protect People: Basic Advice for Stopping the Spread of Avian Flu
Provides advice for workers and others to minimize animal-to-animal and animal-to-human spread of disease. [PDF - 70.3 KB]
Academy for Educational Development Avian and Pandemic Influenza Behavior Change Communication Tools
Provides brochures, fact sheets, and posters for farmers in different countries.
Related NIOSH Publications and Presentations
Avian Influenza: Worker Health and Safety (Presentation)
Disclaimer: The findings and conclusions in this presentation are those of the author and do not necessarily represent the views of the National Institute for Occupational Safety and Health
PDF
only [PDF - 211 KB]
NIOSH presentation at the North
Atlantic Poultry Health and Management Conference, Windsor Locks, Connecticut,
May 10, 2005. This presentation includes avian influenza information
about responder recommendations, medical guidance for poultry workers, and
guidance on personal protective equipment.
Histoplasmosis — Protecting Workers at Risk
DHHS (NIOSH) Publication No. 2005-109 (2004)
This revised booklet provides updated information about worker exposure to
the disease-causing fungus Histoplasma capsulatum. It provides information
about histoplasmosis, identifies activities that may put workers at risk, and
provides recommendations for disease prevention and protection of workers.
En
Español
NIOSH Respirator Selection Logic 2004
DHHS (NIOSH) Publication No. 2005-100 (2004)
This document provides guidance to respirator program administrators on respirator selection. It incorporates the changes necessitated by the revisions to the respirator use and certification regulations and changes in NIOSH policy. This guidance is not intended to be used for the selection of respirators to protect against infectious agents or chemical, biological, radiological or nuclear agents of terrorism.
Interim Recommendations
for the Selection and Use of Protective Clothing and Respirators Against
Biological Agents
DHHS (NIOSH) Publication No. 2002-109 (2001)
This document contains recommendations for personal protective equipment used
in given exposure conditions based on current understanding at the time of publication.
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